Assessing potential health impacts from toxins
Endocrine disruptors (EDs) can cause the alteration of function within the endocrine, or hormone system. Of particular concern is the potential gene deregulation in developing testicular tissue that may be expressed in gamete formation. The application of four parameters was assessed as an indication of the effect of EDs on male gamete production in developing gonads or testes. Firstly, the average number of cells that are to undergo programmed cell death or apoptosis was determined. Potentially, candidate cells during male germ cell differentiation include spermatogonia that are sensitive to changes in their nurse or Sertoli cells. Further on in development the spermatids are particularly sensitive to temperature and hormone levels. Further indicators of disruption to mature gamete production include tubule diameter decreases when levels of apoptotic cells increase. Also, germ cells that give rise to sperm are in the lining or epithelium of the testis tubules. Sometimes, these germ cells proceed more slowly through their development or they are affected by diminished Sertoli cell function. Lastly, the presence of diploid spermatids (possessing two sets of chromosomes) means that one crucial cell division has been skipped and they will give rise to gametes with twice the normal amount of DNA. Using this system of analysis, the potential adverse effects of substances suspected to alter male reproductive function can be assessed, and moreover an evaluation of their impact on human and animal health can be performed.
